The invention pertains to a guide track for a movable windowpane, especially for a retractable windowpane of a motor vehicle.
A window lifter for raising and lowering a windowpane of a motor vehicle is known from DE 19 859 706 A1. Two guide elements are arranged at the lower edge of the pane by clamping or bolting on. Each of the two guide elements is displaceably mounted in a guide track. To the maximum extent possible, these two guide tracks are arranged mutually parallel yet separated inside the door of the vehicle. The guide elements can be raised and lowered along the guide tracks by means of a cable pull by operation of a crank handle or an electric motor. In addition, the guide elements are rigidly coupled together by a tie-bar. By means of the tie-bar, tilting of the guide elements in the tracks due to external tilting moments acting upon the guide elements during operation should be opposed and therefore smoother running of the guide elements in the guide tracks should be realized.
In the installation of window lifters with two guide tracks in the door of a vehicle or some other part of the body, installation difficulties can be encountered when the access openings are very small or the windowpanes are very tall and the guide tracks are commensurately long.
Proceeding from the prior art, the fundamental objective of the present invention is to create a guide track for a movable motor vehicle windowpane, especially for a retractable motor vehicle windowpane, that has compact installation dimensions and at the same time sufficient length for guiding the windowpane during its movement.
This objective is realized with a guide track for a movable motor vehicle windowpane.
According to the invention, by the design of the guide track for a movable windowpane it is achieved that the installation of the guide track can be accomplished with the windowpane retracted and guiding of the windowpane is ensured in both the closed or the open state, with the guide track extended. Therefore, the guide track according to the invention can be inserted through smaller access openings in motor vehicle doors or other parts of motor vehicle bodies. These guide tracks, eventually preassembled with other components into a module, can then also be inserted into the door without further installation aids. Due to the smaller dimensions of the guide tracks, the installation can be advantageously accomplished more quickly, and at the same time the risks are minimized of bumping against the body or other parts with the guide track during its installation, which could require costly reworking. With such a retractable guide track, it is also possible to use guide tracks when motor vehicles have especially tall and obliquely configured side windows.
It is advantageous for the guide track to be fashioned with a sort of telescoping configuration, with a base track and at least one extension track. The base track, which also determines the maximum length of the guide track, can then, e.g., together with other components, be pre-mounted on a catch or module plate before the latter is installed in the door of the vehicle. The extension track is inserted into the base track and can be moved out beyond the base track to achieve the required extension of the track. The extension track can be extended only partially beyond the base track, so that the base track can maintain the stability.
The extension track is advantageously designed so as to be movable beyond both ends of the base track, whereby an extraordinary reduction of the overall length of the base track and therefore of the guide track can be achieved which otherwise would need a further extension track and in turn would be more complicate as well as a much weaker construction.
In a special configuration of the invention, the extension track is not carried directly in the base track, but rather is carried by way of a slide element. Here the length of the slide element is less than that of the base track, preferably a fifth of the length of the base track, and is displaceable only to the respective ends of the base track. Appropriate stops are located at the ends of the base track.
In order to arrive at a compact configuration of the guide track, the base track and the slide element are designed with a C-shaped cross section. The slide element then rides in the base track and the extension track rides in turn in the slide element. In a further refinement, the extension track can also be designed with a C-shaped cross section, so as to guide the guide element for mounting the windowpane in its interior. Here the length of the guide element for the windowpane is again less than the extension track, preferably about a fourth of the length of the extension track, and can move along the extension track to its respective ends. Stops are provided at the ends of the extension track to limit the travel of the guide element.
For the design of the guide track with the extension track telescoping out of the base track at both ends, comparable travel of the slide element in the base track is also necessary. This displacement movement is effected especially simply with catches located in the vicinity of the ends of the extension track. These catches also limit the travel of the extension track relative to the slide element.
Advantageously, the guide track and the base track are made of metal and the slide element and the guide element are each made of plastic.
The guide track according to the invention is especially well suited for use in a device for lowering and raising a windowpane of a motor vehicle, especially for raising and lowering a windowpane of a motor vehicle door, which has two essentially parallel guide tracks running separated from each other. In the case of such devices the guide elements of the two guide tracks are advantageously joined together by a tie-bar and connection elements for the windowpane are located on the tie-bar. For connection of the tie-bar to the guide element, the guide element is designed with two slide parts with an essentially rectangular form. The slide parts are arranged parallel to and separated from each other and are connected by a joint as well as rotated by 90xc2x0 in relation to each other. Then the first slide part can conveniently ride in the C-shaped extension track and, with comparable configuration of the tie-bar with a C-shaped cross section, the second slide part can be inserted into the undercut of the C-shaped tie-bar. Compensation of angular errors is possible by means of the joint.
The aforementioned as well as claimed components described in the embodiment and to be used according to the invention, are not subject to any particular exceptional circumstances with respect to their size, design, material selection and technical conception, such that the selection criteria known in a respective field of application may find unlimited use in the scope of the claims.